The present invention relates generally to peripheral equipment such as a storage unit that can be disconnected from host equipment in a computer system and can hold a storage medium. More specifically, the invention relates to a personal computer connected to a detachable storage unit, and to a method of ejecting a medium from the storage unit.
Computer technology is advancing in many fields, including home appliances, and from compact disks (CDs) to devices recording still pictures and video onto disks and tapes. Under such circumstances, an interface complying with IEEE 1394 standards (hereinafter written as “IEEE 1394”) is drawing attention as a popular high-speed serial interface as a substitute for a SCSI (small computer system interface). IEEE 1394 connectors are a general purpose interface used to transfer digital data to and from a small computer, a storage medium (e.g., magnetic disk (HDD), magnetic-optic disk (MO), magnetic tape) and a printer for personal computers (hereinafter abbreviated as “PCs”) and work stations. The IEEE 1394 interface is preferred because it can be used with multi-media applications which were impossible to use with the SCSI.
The use of the IEEE 1394 interface can be roughly divided into two fields of application: an interface for PC peripheral equipment and an interface in the field of home appliances (particularly, for AV (audio-visual) applications). The IEEE 1394 interface can be used to connect PCs to home appliances. The features of the IEEE 1394 interface can be summarized as follows:                (1) multi-media transfer (isochronous transfer) support;        (2) speed corresponding to dynamic pictures (cable versions, 800 Mbps, 1600 Mbps, 3200 Mbps);        (3) automatic configuration (plug-and-play);        (4) host PC is not always needed;        (5) use of a device bay rather than cable connections;        (6) peer-to-peer connections;        (7) hot plugging possible;        (8) topology (tree structure) with a high degree of freedom;        (9) termination unnecessary; and        (10) generally usable for packet communication.        
Among these features, plug-and-play did not exist in conventional interfaces. When the power source plug is connected to an outlet for an IEEE 1394 interface, the equipment starts immediately and is ready for use, offering convenience. In addition, since hot plugging is possible, the user can connect or disconnect the cable while the PC is still running and does not have to restart the PC each time the cable to the peripheral is disconnected and connected.
The device bay is a new feature and includes a standard extension slot which greatly improves plug-and-play by facilitating the mechanical connection between the devices. With a device bay, it is possible to incorporate peripheral equipment in the PC without opening the housing of the PC or without turning off the power source of the PC. Thus, the user will find it more convenient to use. Various storage units can be inserted in the device bay including a hard disk unit.
However, whether the peripheral is connected to the PC by cable or device bay, the systems capable of disconnecting peripheral equipment without turning off the power of the host equipment, as with the IEEE 1394 interface, have a number of problems.
First, since the peripheral equipment has plug-and-play and hot plugging, it is easy to move peripheral equipment by disconnecting the power source plug and connection cables. A user may connect cables to peripheral equipment to store or read data or execute a particular job but may then disconnect the cables when the job is finished to transport the peripheral equipment to another place. Therefore, when a removable medium such as floppy disk or magneto-optic disk remains inserted in the peripheral equipment while transporting the peripheral equipment, the actuator mounting a read/write head may move due to vibration while transporting the peripheral equipment, whereby the head may collide with the medium, often causing damage to the peripheral equipment or the medium.
Second, the storage units that can be inserted in a device bay without opening the housing of the PC can be easily used, removed and even replaced without authorization. Currently, no measures exist to prevent unauthorized use or theft of these types of storage units.